In the semiconductor field, each set of wafers fabricated is typically performance tested, before they are diced into individual integrated circuits. FIGS. 1-4 show equipment that is used in this testing. Although these figures show an embodiment of the invention they also show some features that are shared with prior art systems. These features are referenced in this section to help explain the context of the invention.
To perform wafer testing a piece of equipment known as a probe station 10 has a head plate 12 that defines an original head plate aperture 14 FIG. 3. The aperture supports a circular device known as a probe card dish 16, which in turn supports the probe card 17. A separate piece of equipment, known as a tester 18 having docking units 20, is lowered into mating position with respect to the probe station, the probe card dish and the probe card. Sometimes probe station 10 includes an obstacle, such as a wafer loader cover 19, that is too close to the original-head plate aperture 14 to permit the docking of a particular tester 18.
Generally, a number of guides and associated docking equipment pieces are needed to successfully dock a tester to a probe station, a probe card dish and the wafer that the probe card dish supports. Probe stations are generally sold to semiconductor manufacturing facilities with this docking equipment already installed. Accordingly, when a new tester is purchased it is typically necessary to purchase a new probe station fitted with docking equipment to facilitate docking with the new tester. Unfortunately, the docking equipment, which is typically installed by the probe station vendor or a secondary source, generally permits docking to a single make of tester. The installation of docking equipment to permit the use of a different tester with the probe station is referred to in the industry as xe2x80x9chardware swap-outxe2x80x9d and results in extensive use of technician time and equipment down time.
It is known to machine a single prober to accept a single tooling plate that permits docking to a desired tester. There appears, however, not to have been an effort in the prior art to produce a set of standardized tooling plates that could each be used on any one of a set of differing probe stations. As a result, only very limited flexibility was gained by this method.
Another issue facing semiconductor manufacturers is the lack of uniformity of head plate apertures, between the various commercial lines of probe stations. The unfortunate result is that there is currently no known technique for mating a probe station having a first head plate aperture size with a tester designed to mate with a prober having a second head plate aperture size.
In a first aspect, the present invention is a method of retrofitting a probe station having a head plate, so that the probe station is adapted to mate with a predetermined probe card dish and any tester out of a set of testers. A depression is machined into the head plate to create a head plate-tooling plate attachment region. Next, fastening and alignment items are provided and installed in this region. Further, a set of tooling plates is provided, each having fastening and alignment items adapted to mate to the fastening and alignment items on the attachment regions and defining an aperture designed to engage the predetermined probe card dish. The user may then select a desired one of the tooling plates and mate and fasten the selected tooling plate to the head plate-tooling plate attachment region using the alignment and fastening items.
In a second separate aspect, the present invention is a tooling plate for installation into a probe station. The plate comprises a rigid plate defining a major aperture and a set of peripheral apertures fitted with spring loaded, retained screws adapted to facilitate fastening to mating threaded holes.
In a third separate aspect, the present invention is a tooling plate for installation into a probe station, the plate comprising a rigid plate defining a major aperture and a set of dowel locater holes precisely set with respect to the location of the major aperture.
In a fourth separate aspect, the present invention is a method of retrofitting a probe station having a head plate that defines an original head plate major aperture, so that the probe station is adapted to mate with a predetermined probe card dish and a predetermined tester that the probe station could not mate with prior to being retrofitted. The method comprises the steps of machining a depression into the head plate to create a head plate-tooling plate attachment region. In addition, the head plate major aperture is enlarged and head plate-tooling plate attachment region fastening and alignment items are provided. Also provided is a tooling plate having tooling plate fastening and alignment items adapted to mate to the head plate-tooling plate attachment region fastening and alignment items and defining a tooling plate major aperture designed to engage the predetermined probe card dish and wherein the tooling plate major aperture is positioned relative to the tooling plate fastening and alignment items such that once the tooling plate is installed the tooling plate major aperture will not be coincident to the original head plate major aperture. Finally, the tooling plate is mated and fastened to the head plate-tooling plate attachment region, using the alignment and fastening items.
In a fifth separate aspect, a method of retrofitting a probe station having a head plate, so that it can mate with a tester that includes docking equipment that extends horizontally beyond the horizontal extent of the probe station. The method comprises machining at least one attachment region into the head plate and fitting the attachment region with alignment and fastening items and providing at least one docking equipment attachment plate, including a piece docking equipment, to mate to the attachment region. Then the docking equipment attachment plate is mated to the corresponding attachment region so that the docking equipment attachment plate protrudes horizontally outwardly from the head plate and supports the piece of docking equipment outwardly of the headplate.
In a sixth separate aspect, the present invention is a probe station capable of mating to a tester that has a larger footprint than the probe station. The probe station includes a headplate and at least one docking equipment supporting plate that extends outwardly from the headplate and supports at least one piece of docking equipment at a location distanced from the headplate.
In a seventh aspect, the present invention is a method of retrofitting a probe station having a head plate, so that the probe station is adapted to mate with a predetermined probe card dish and any tester out of a set of testers. Fastening and alignment items are provided and installed on the head plate. Further, a set of tooling plates is provided, each having fastening and alignment items adapted to mate to the fastening and alignment items on the head plate and defining an aperture designed to engage the predetermined probe card dish. The user may then select a desired one of the tooling plates and mate and fasten the selected tooling plate to the head plate using the alignment and fastening items.